Ceramic foam filters used in aluminium casting
Ceramic foam filters are designed to ensure high purity of blank casting of aluminum alloys at metallurgical plants and for filtering aluminum castings in foundries.
Filters have a three-dimensional structure of interconnected pores forming a labyrinth of the ceramic filter body. Filters are distinguished by a homogeneous ceramic structure with a minimum of blocked places on both working surfaces.
In this way, optimal conditions are created for the effective operation of all filtering mechanisms.
The chemical composition of Al2O3-based filter ceramics provides an efficient trapping of undesirable impurities, especially inclusions of a similar composition (oxide traps).
Due to its high stability, even with prolonged exposure to high temperatures, filters can be successfully used in filtration boxes or in heating furnaces for filtering large volumes of liquid metal.
Foundry filters can be installed in the filter chamber of the gate system of the mold or used for direct casting technology of castings through an insulating or exothermic insert. They can be combined with insulating sprues made of ceramic fibers.
Filters can be easily placed in the risers in the case of low-pressure casting technology. A special type of filter for this technology is the so-called “filter plugs”.
Filters can be successfully used for continuous immersion in the melt, for example, as filter baffles in chamber heating furnaces.
Metallurgical filters are produced in the form of a truncated pyramid; main dimensions are in inches. The beveled side walls serve as a supporting surface for landing in a ceramic filter box.
In addition to the standard filter sizes, it is possible to supply filter segments of various sizes and shapes without beveled sides, which in most cases are loaded in a vertical position into the filter boxes or in the lining of furnaces. It is recommended to equip all types of filters with sealing or expansion tape, which ensures that the filter is firmly fixed in the correct position.